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1985 300D Turbo
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Discussion Starter · #1 · (Edited)
Hey everyone,

I've had my W123 for 18 months now, and finally have enough data to start running some numbers. I'm quite interested in the general concept of how much it costs per mile you drive. This excludes fuel and insurance because these are a bit arbitrary and are present with any car you own. The general idea is that the initial purchase price causes the early miles to be expensive. Meanwhile, the rate to which this falls is contingent on miles driven plus average maintenance costs.

I've found that my car requires about $0.15 for maintenance per mile traveled. This is partly true because my car was quite well restored when I bought it (and hence had a relatively high purchase price). In any event, here is a chart I created to predict the costs for miles that I drive. I'm presently at 20,000 miles that I've put on (and thus just below $0.50/per mile).


If anyone is interested in doing the same for their car, I can put together an excel sheet that you can use to plot out your own costs over time.
 

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1983 300D Turbo Diesel
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thats a great idea. i definitely would be interested in your excel sheet. can you e-mail it to me at [email protected]? i have a 1983 300D
 

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1985 300td, 1983 Datsun Maxima Diesel
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Hey everyone,

I've had my W123 for 18 months now, and finally have enough data to start running some numbers. I'm quite interested in the general concept of how much it costs per mile you drive. This excludes fuel and insurance because these are a bit arbitrary and are present with any car you own. The general idea is that the initial purchase price causes the early miles to be expensive. Meanwhile, the rate to which this falls is contingent on miles driven plus average maintenance costs.

I've found that my car requires about $0.15 for maintenance per mile traveled. This is partly true because my car was quite well restored when I bought it (and hence had a relatively high purchase price). In any event, here is a chart I created to predict the costs for miles that I drive. I'm presently at 20,000 miles that I've put on (and thus just below $0.50/per mile).


If anyone is interested in doing the same for their car, I can put together an excel sheet that you can use to plot out your own costs over time.
Hi

You've done some interesting work here.

I would point out that what you are showing is the out of pocket expense per mile rather than true cost per mile.

The reason for that is that you have included the total initial cost of the car but have not allowed for the remaining value of the car at any given mileage.

From your chart it appears that you paid a little over $6000 for your car. But at the end of 20,000 miles she may still have a resale value of $5000 - resulting in an actual cost of $1000 plus $.15/mile for the 20,000 miles - or $4000 divided by 20,000 miles = $.20/mile.

With these 123s, it is even possible that a well maintained car could have a resale value equal or greater than the purchase price after say 60,000 miles of use.

Of course the out-of pocket expense per mile is also a worthwhile and valuable indicator.

Regards, Joseph
 

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1985 300D Turbo
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Discussion Starter · #5 · (Edited)
I would point out that what you are showing is the out of pocket expense per mile rather than true cost per mile.
Yes, you are right. I've excluded fuel and insurance costs, as well as the value of the vehicle itself. The main thing I was trying to get at with the maintenance costs plus initial purchase was the thought that this is the best way to compare "total cost of ownership." This is useful to help new buyers price their purchase, for current owners to consider more DIY, or for when a car isn't worth it. For example:
  1. Someone may buy a $2,000 W123, but their maintenance costs are going to be higher.
  2. The next point to compare is DIY versus mechanics. Someone who takes their W123 to the mechanic for everything would be interesting to see how expensive that is versus mixed DIY/mechanic versus 100% DIY.

From your chart it appears that you paid a little over $6000 for your car. But at the end of 20,000 miles she may still have a resale value of $5000 - resulting in an actual cost of $1000 plus $.15/mile for the 20,000 miles - or $4000 divided by 20,000 miles = $.20/mile.
Nice work, you are correct: I paid $6250.

If we get away from comparing vehicles and just look at "true cost" of ownership as you say, then fuel, insurance, and sell price need to be added. The insurance variable will just be an average cost per mile in the same way maintenance costs are averaged out. Fuel is the most challenging because you can't predict it going forward. I have not yet done a margin of error on the maintenance costs (I'll do it tonight!) but for fuel the margin of error could be 100% or more!
 

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1983 Mercedes 300DT 301500 miles
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how about cost of tires? It's kind of like fuel and insurance every car need's it :)
I believe that for the 37-38k miles that I have driven my c class i have spend about the same (700-800$) for parts and oil and about as much for tires.
 

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SLK 230K auto
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Woooao!

You are very number minded, me too. But from my experience running classic cars i don´t see much point in trying to get real accurate with the spreadsheet.

My reasons:

- The emotional value of having a real different car is difficult to asses but surely pretty high for most of us.
- The time spent cleaning, mending and in general around the cacr other than dirving it, has double entry on the spreadsheet one is cost per hour (put your own personal rate) and the other enjoyment per minute (put estimated personal revenue per enjoyment)
- Future cost of maintenace is a function of how much you love you car wich again functions how much money will you spend to put everything right as it goes.
- Resale value could be real high if you select carefully the car and model. My, i think that w123 coupes, and even berlinas, are fast becoming true classics with future prices to match.
- Finally we are in the middle of an uncertain crisis so just relax and enjoy your pride and joy


The Classic accountant
 

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'77 6.9, 74 240D, 96 Ram 5.9L Cummins
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Since it seems to be some sort of linear value it doesn't address issues like CV joint replacements, winshields, transmission issues, vaccum pump rebuild, busted window lifts, etc. and things of that nature.
 

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money pits of various forms
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Cost analysis? You sound like a disbeliever, would you like some koolaid?
 

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1985 300D Turbo
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Discussion Starter · #10 ·
Tedd300DT: The cost of tires is included in my maintenance costs. In my case, I actually replaced my tires right after I bought the car. After 18 months of maintenance work, I feel like I've done enough between replacing aging parts (25 year old hoses, etc) to standard maintenance items (fluids, tires, oil, etc) to have a fair estimate for future costs.

Clasico: Ah, numbers. :) I enjoy compiling them, graphing curves, and so on. They do provide a useful guide for knowing that my costs are within reason as well and help contextualize my premise that the W123 is an affordable vehicle over the long run. Your logic about excluding personal time spent making the total cost less than accurate is sound. Of course, I don't care about the time I spend maintaining the car because it is fun. :)

diametricalbenz: It is fairly linear because I have simply averaged maintenance costs. I have 18 months worth on my own dime. My 18 months don't cover every scenario, and I'm going to do a margin of error tonight, but I've done enough that it is possible to make a plausible estimate that I think can withstand the test of time. That said, I'd love to see numbers from other people. :)

winmutt: ROTFLMAO
 

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1985 300td, 1983 Datsun Maxima Diesel
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[*] The next point to compare is DIY versus mechanics. Someone who takes their W123 to the mechanic for everything would be interesting to see how expensive that is versus mixed DIY/mechanic versus 100% DIY.

I think you just might be onto something really useful here! A way of predicting future maintenance cost for an individual car.

There are a number of maintenance and repair jobs that owners of 123s can reasonably expect to encounter during ownership.

Just to pull a few out of the air - Half axle replacement, valve adjustment, oil change, Ball joint & tie rod replacement, Control arm bushing replacement, starter replacement, tire replacement, battery replacement, wheel alignment, seat repair, air conditioner repair, Brake system repair, Injector & glow plug replacement - and a dozen or so more.

Then each job could be priced both as DIY jobs and Mercedes Dealer jobs - and the information posted to be available to all..

With this information in hand, a prospective buyer (or seller) would have a basis for deciding the value of the car in question. If the previous owner had already recently completed most of the jobs then the car would be worth a premium price - if most of the jobs had been neglected -- well;

Keep up the good work!

Joseph








We know
 

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'73 450SL, '83 300CD, '01 E320 4matic
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[*] The next point to compare is DIY versus mechanics. Someone who takes their W123 to the mechanic for everything would be interesting to see how expensive that is versus mixed DIY/mechanic versus 100% DIY.
This is an important point. My cars are all 100% DIY. The only thing that I'd pay to have done is tires mounted or an alignment.

My 300CD cost me $1000, and I put 61,000 miles on it. Cost of ownership was dirt cheap. I probably put $500 on misc. brake pads, junkyard parts, and oil changes. I spent 300 on tires, 200 on rims (which I have used on my new 123). So that $500 does not count. But even if I do count it, $2000/61000 miles is 3.2 cents per mile!

I used my car primarily for work, so the fuel costs were paid by my employer.

Counting fuel costs would raise it considerably. At an average 25 mpg, I would have used 2440 gallons of diesel fuel to go 61k miles. At $3 a gallon, that's $7320. $7320/61000 = 12 cents per mile.

So my total ownership of my last 123 cost me 15.2 cents per mile INCLUDING fuel costs. Still not bad at all.

Now the W126 and 107 are another story.
 

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It cost me about $100 a month in old car maintenance. This figure doesn't includ expendibles like brakes and tires, fuel, car washes, but does include oil changes and other fluid flushes/changes.
 

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1985 300D Turbo
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Discussion Starter · #14 · (Edited)
Okay, I've found a standard deviation of 5.4% for the costs I've projected versus my actual costs to date. Not bad. :) Enclosed is the plot of my actual costs at actual mileage counts that I've put on the car versus the projected values at those counts.
 

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Discussion Starter · #15 ·
I think you just might be onto something really useful here! A way of predicting future maintenance cost for an individual car.
Exactly! This was my original intent. :)

With this information in hand, a prospective buyer (or seller) would have a basis for deciding the value of the car in question. If the previous owner had already recently completed most of the jobs then the car would be worth a premium price - if most of the jobs had been neglected -- well;
Precisely. :)

I'm going to upload an excel sheet that others can use, and hopefully we can get a good data set.
 

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Discussion Starter · #16 · (Edited)
Okay, I've put together a basic spread sheet that folks can use (made in Excel 2007). You only need to enter four basic data points. It is essential that the data you enter are accurate, otherwise don't expect the results to be accurate. :)

For people that have real data (e.g. you have tabulated the costs on all your maintenance records) I'm very interested to know:
  1. Your maintenance cost per mile
  2. Your purchase price (for determining the relationship between the two)
  3. How long you've owned your car
  4. If you are DIY, mechanic only, or in-between
  5. Condition of your car: (A) Show room quality; (B) Well maintained daily driver; (C) Road Warrior

I'm trying to create good comparisons. Obviously someone planning to drive their car into the ground is going to neglect all maintenance and thus have a low cost per mile, while a collector is going to spend money on *everything* and not drive the vehicle much, and thus have a high cost per mile. As for me:

  1. Maintenance cost per mile: $0.15
  2. Purchase price: $6,250
  3. Miles put on: 18,000
  4. DIY/mechanic only/in-between: In-between
  5. Condition of your car: Daily Driver
 

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